Response analysis of TLD-300 dosimeters in heavy-particle beams

• Published in: Physics in medicine & biology Vol. 41; no. 9; pp. 1665 - 1678
• Main Authors: Loncol, Th, Hamal, M, Denis, J M, Vynckier, S, Wambersie, A, Scalliet, P
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.09.1996; Institute of Physics
• Subjects: Applied radiobiology (equipment, dosimetry...); Biological and medical sciences; Biological effects of radiation; Carbon; Cobalt Radioisotopes; Cyclotrons; Fundamental and applied biological sciences. Psychology; Humans; Linear Energy Transfer; Luminescent Measurements; Models, Theoretical; Neutrons; Phantoms, Imaging; Protons; Quality Control; Radiotherapy - methods; Radiotherapy - standards; Radiotherapy Dosage; Sensitivity and Specificity; Space life sciences; Tissues, organs and organisms biophysics; Water; Test objet; Radiosensitivity; Cesium; Radioisotope; Radiotherapy; Linear energy transfer; Heavy element; In vivo; High energy radiation; Proton beam; Instrumental response; Treatment; Neutron beam; Thermoluminescent dosimeter; Medical application; Comparative study
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/41/9/007

In vivo dosimetry is recommended as part of the quality control procedure for treatment verification in radiation therapy. Using thermoluminescence, such controls are planned in the p(65) + Be neutron and 85 MeV proton beams produced at the cyclotron at Louvain-La-Neuve and dedicated to therapy applications. A preliminary study of the peak 3 (150 degrees C) and peak 5 (250 degrees C) response of CaF2:Tm (TLD-300) to neutron and proton beams aimed to analyse the effect of different radiation qualities on the dosimetric behaviour of the detector irradiated in phantom. To broaden the range of investigation, the study was extended to an experimental 12C heavy ion beam (95 MeV/nucleon). The peak 3 and 5 sensitivities in the neutron beam, compared to 60Co, varied little with depth. A major change of peak 5 sensitivity was observed for samples positioned under five leaves of the multi-leaf collimator. While peak 3 sensitivity was constant with depth in the unmodulated proton beam, peak 5 sensitivity increased by 15%. Near the Bragg peak, peak 3 showed the highest decrease of sensitivity. In the modulated proton beam, the sensitivity values were not significantly smaller than those measured in the unmodulated beam far from the Bragg peak region. The ratio of the heights of peak 3 and peak 5 decreased by 70% from the 60Co reference radiation to the 12C heavy-ion beam. This parameter was strongly correlated with the change of radiation quality.